[Whiskeyjack91]

my 92 4x4 auto wont charge. brand new pcm, brand new alternator, brand new cps. still no grid heater still wont charge wiring between alternator and pcm look to be good couldnt find any grounds or opens. when green wire of alternator plug grounded with jumper wire, alternator charges 15+ volts. any ideas? please help :confused013:

 

[Shibbyutman]

did you replace the external voltage regulator?

are all your ground in good shape? cab grounded to engine? engine grounded to batteries? frame grounded to cab?

 

[9297oldram]

did you replace the external voltage regulator?

are all your ground in good shape? cab grounded to engine? engine grounded to batteries? frame grounded to cab?

Doesn't have a external regulator unless someone has put one one to replace the ECM.

There is a ASD relay on the inside of the left fender the one closest to the front. When the ECM gets a signal from the CPS then the ASD opens.

Is the CPS gapped at .050?

 

[Shibbyutman]

Damn, different than my 89. Sorry, carry on :w:

 

[DodgeW250]

It could be that the wiring is "red-neck rigged" and fried your ECM in that case you should probably re-wire the whole thing and get a new ECM or put an external regulator on it to replace the ECM.

 

[Whiskeyjack91]

all wiring is original, and its already a brand new pcm. ill give the asd relay a try, cps is at .050"

 

[Steve g]

Highly unlikely to be the ASD relay as that provides batt voltage to the field circuit. If there was no voltage to the field circuit grounding out the other field terminal wouldn't result in the alt charging.

You need to get the pinout diagram for the ECM plug. I have one, but it's on my home pc and I'm out of town until next Mon. That and a multimeter (volts and ohms at least) will let you track this down.

What you are looking for is the 4 pins that provide power and ground to the ecm. There is one with batt+ all the time, one with batt+ key on and 2 ground pins. You check them all with a volt meter and make sure you have correct voltage (no voltage drop, reverse polarity of tester to check grounds) at all pins. Once you have ensured all that is good you can check for continuity to the alt field wire. Check for continuity to the cps. If all those check out I would suspect a bad ecm, but most likely you are going to find a wiring issue.



Steve g